Patent GB-374480-A (GB)
Title: Improvements in web feeding mechanism for wrapping machines
IPC: B65B41/18
Filed: 1931-02-07
Abstract: 374,480. Feeding webs. JOHNSON AUTOMATIC SEALER CO., Ltd., Battle Creek, Michigan, U.S.A. Feb. 7, 1931, No. 3974. Convention date, March 12, 1930. [Class 100 (i).] In a web-feeding mechanism for wrapping machines of the type in which the feed of the web is automatically controlled by electrical devices, driving means are provided for operating the web-feeding rolls, having a clutch, for controlling the operation of the driving means, which is itself controlled by means including an electrical device, the resistance of which is varied by variations of light. The web 21 passes over tensioning rollers 38, 39, 40, Fig. 4, to the feeding rollers 23, 24 and thence to cutter rollers 14, 18. The continuouslydriven shaft 13 of the roller 14'drives the shaft 17 carrying the roller 18 and, through an idler gear 107, Fig. 3, a gear 103, 'loose on the shaft 96 of the roller 23, which is integral with a clutch part 94, of which the coacting part 93 is slidably mounted upon a sleeve on the'shaft 96. At the other end of this shaft is fixed a gear meshing with a gear on the shaft 106 of the coacting feed roller 24, so that when the clutch parts 93, 94 are in engagement the feed rollers 23, 24 will be driven from the shaft 13. Engagement of the parts 93, 94 is effected by the high part 78 of a continuously-driven cam 79, fixed on the shaft 17, striking a roller 76, mounted on a yoke 74, which is pivoted at 75. A plate 80, attached to the yoke 74 carries on a pivot 82, a link 83 on which is loosely mounted a collar 84 ; a yoke 86 is pivotally attached to the collar 84, the yoke being rigidly secured to a clutch-operating lever 89, pivotally mounted on a pin 90. A spring 91 and adjusting nut 92 on the rod 83 yieldably urge the clutch parts into engagement through the lever 89, a yoke 97 on which engages a pin 98 on the sliding sleeve carrying the clutch part 93. The yoke 74 is pivoted at 73 to a member 72 which extends beyond the pivot 73 in both directions, one end engaging a projecting surface on the yoke 74 and the other being connected by a pin-andslot connection with a link 66, slidably mounted in a casing 53 and carrying a spring-pressed collar 65 to which is pivotally attached a latch 60, pivotally connected at its other end to a link 61, attached to the casing. When the arm 89 swings to the right to engage the clutch part 93, 94 under the action of the cam 79, the yoke 74 pulls the link 66 to the right and thereby lowers the latch 60 and link 61 to the position shown in dotted lines in Fig. 3, where they are held by one arm of a detent 56, mounted on a pivot 57. The other arm 55 of the detent is attached to an armature 52, Fig. 4, of a coil 50 connected to the secondary. of a transformer 46. The primary is connected to the photoelectric cell 29, situated on the opposite side of the web 21 to a lamp 31, both being adjustably mounted on the frame of the mechanism, and light impervious spots 30 on the web are provided at suitable intervals in relation to the design &c. thereon. The operation is as follows : The clutch parts 93, 94 are held in engagement by the detent 56 until a spot 30 is positioned between the cell 29 and the lamp 31, when a variation is produced in the secondary current of the transformer 46 to lift the core 52 of the electromagnet 51 and release the detent 56, and thence the latch 60. The link 66 under the action of the compression spring 69 swings the lever 74 about its pivot 75 so that the link 83 through the yoke 86 swings the lever 89 to disengage the clutch parts 93, 94 and stop the rotation of the feed rolls 23, 24 at the instant a line extending transversely between the first two wrappers of the web 21 arrives in the vertical plane of the axes of the cutter rolls 14, 18 so that the latter cut the leading wrapper accurately. The cam 79 in its continued rotation again brings the raised portion 78 into engagement with the roller 76, whereupon the lever 74 swings as before to engage the clutch parts andcontinue the feed until the next spot 30 arrives between the cell 29 and the light 31.